Masahiro Sakaguchi

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Because of a critical shortage in suitable organs, many patients with terminal liver disease die each year before liver transplantation can be performed. Transplantation of isolated hepatocytes has been proposed for the temporary metabolic support of patients awaiting liver transplantation or spontaneous reversion of their liver disease. A major limitation(More)
Co-translational protein translocation across the endoplasmic reticulum membrane is interrupted by particular amino acid sequences which are called stop-transfer sequences. Since the stop-transfer process should reflect the character of the protein translocation machinery, systematic examination on the structural requirements for stop-transfer sequences(More)
Rat liver cytosol contained an activity that stimulated the import of wheat germ lysate-synthesized precursor proteins into mitochondria. The activity was purified 10,000-fold from the cytosol as a homogeneous heterodimeric protein. This protein (termed mitochondrial import stimulation factor or MSF) stimulated the binding and import of mitochondrial(More)
In a current model of integration of multispanning membrane proteins into the endoplasmic reticulum, it is proposed that the transmembrane segments show alternating translocation initiation and stop-transfer functions. Here, we present evidence for a mode of cotranslational insertion in which an internal signal-anchor sequence with Nexo/Ccyt topology(More)
A retrospective review was conducted of 91 patients with deep neck infections to determine the pattern of clinical disease and formulate a management plan. The spaces involved, as determined by clinical, radiologic, and operative findings, were the peritonsillar space (72 patients), parapharyngeal space (eight patients) submandibular space (seven patients),(More)
Coatomer, the cytosolic protein complex, consists of seven subunits (alpha-, beta-, beta'-, gamma-, delta-, epsilon-, and zeta-COP) and is involved in vesicle trafficking early in the secretory pathway in collaboration with a 20 kDa GTP-binding protein (ARF). In the present study, we have identified a yeast gene which encodes a protein having 39% amino acid(More)
The overexpression of reduced expression in immortalized cells (REIC)/Dickkopf-3 (Dkk-3), a tumor suppressor gene, induced apoptosis in human prostatic and testicular cancer cells. The aim of this study is to examine the potential of REIC/Dkk-3 as a therapeutic target against breast cancer. First, the in vitro apoptotic effect of Ad-REIC treatment was(More)
Mitochondrial import stimulation factor (MSF) unfolds wheat germ lysate synthesized aggregated mitochondrial precursor proteins and stimulates their mitochondrial import in an ATP dependent manner. Here we analysed the function of MSF mainly by utilizing chemically pure adrenodoxin precursor (pAd). MSF bound to the unfolded pAd and prevented it from losing(More)
A cDNA clone encoding a Na(+)- and Cl(-)-dependent high affinity taurine transporter was isolated from a common carp cell line, Epithelioma papulosum cyprini (EPC), as a hyperosmotic stress-inducible gene by RNA arbitrarily primed PCR. The clone contained a 2.5-kb cDNA fragment including an open reading frame of 1878 bp encoding a protein of 625 amino(More)
The Arabidopsis thaliana AtHKT1 protein, a Na(+)/K(+) transporter, is capable of mediating inward Na(+) currents in Xenopus laevis oocytes and K(+) uptake in Escherichia coli. HKT1 proteins are members of a superfamily of K(+) transporters. These proteins have been proposed to contain eight transmembrane segments and four pore-forming regions arranged in a(More)